Kermetico C7 Convertible HVAF | HVOF System for Spraying Metal and Carbide Coatings onto Large Parts
The C7 HVAF / HVOF system is designed to deposit metal and cermet coatings onto external surfaces of various workpieces and structures.
It is a heavy-duty torch, made to endure harsh thermal spray environments and spray long hours with high throughput.
A Microstructure of a C7 HVAF WCCoCr 86/10/4 Coating: No Gas Permeability at 300 PSI, Hardness 1,180 HV300
HVAF Process Description and Advantages
The C7 HVAF-HVOF gun sprays powders, heated and accelerated by the oxy-fuel or air-fuel gas combustion products.
The mixture of compressed air, oxygen (in HVOF system mode) and the fuel gas flows into the combustion chamber through the orifices of a catalytic ceramic insert. The compressed air cools the chamber when entering the gun. Then the preheated air is used for mixing with the fuel for combustion.
Compressed air from an additional line cools the front of the chamber and the nozzle assembly.
Initial ignition of the mixture results in heating of the ceramic insert above the mixtures’ auto-ignition temperature and then the hot insert continuously ignites the mixture.
The spray powder is injected axially into a wide combustion chamber, where the gas flow is comparatively slow, less than 40 m/s (130 ft./sec.).
Having a long residence time and being exposed to favorable heat transfer conditions at high gas pressure, the powder is efficiently heated in the chamber.
As an optional tool for proper heating, controlled amounts of a high heat conductivity gas (hydrogen or helium) may be injected into the powder carrier gas.
The powder exiting the chamber is propelled into the nozzle of chosen length and configuration, where it is accelerated to a velocity that may be over 1,000 m/s (3,300 ft./sec.).
When impacting a substrate, the spray powder particles form a coating.
Blast & Spray
Each Kermetico AK HVAF gun can be used in blast and spray operations.
You can eliminate blasting and masking for blasting in a different booth. Just prepare a part for coating, blast it with any AK gun (it is extremely fast and uniform) and spray with the same gun, spending 10x less time for the blasting operation.
It is much faster and more accurate than manual blasting. Furthermore, using HVAF blasting for surface preparation reduces blast media consumption by 100-times compared to blasting with compressed air.
